EDN Laboratory

Segev Y., Pitzer M., Karpov M., Akerman N., Narevicius J. & Narevicius E. , "Collisions between cold molecules in a superconducting magnetic trap", (2019) Nature. 572, 7768, p. 189-193

We decelerate and trap molecular oxygen using time-dependent magnetic fields and superconducting magnets. The density-dependent, non-exponential decay in particle number provides a clear proof of molecule-molecule collisions within the trapped ensemble. The spatial distribution of molecules in the trap is found to change over time, allowing to set limits on the ratio between the elastic and inelastic collision cross sections. Our experimental scheme opens up new possibilities for studying quantum effects in chemistry as well as for evaporative cooling of molecules.

Paliwal P., Deb N., Reich D. M., Avoird A. v. d., Koch C. P. & Narevicius E. , "Determining the nature of quantum resonances by probing elastic and reactive scattering in cold collisions", (2021) Nature Chemistry. 13, 1, p. 94-98

A. Blech, Y. Shagam, N. Hölsch, P. Paliwal, W. Skomorowski, J. W. Rosenberg, N. Bibelnik, O. Heber, D. M. Reich, E. Narevicius & C. P. Koch , "Phase protection of Fano-Feshbach resonances", Nature Communications   21 Feb 2020: Vol. 11, 999 (2020)

A. Klein, Y. Shagam, W. Skomorowski, P.S. Zuchowski, M. Pawlak, L.M.C. Janssen, N. Moiseyev, S.Y.T. van de Meerakker, A. van der Avoird, C.P. Koch, E. Narevicius, "Directly probing anisotropy in atom–molecule collisions through quantum scattering resonances", Nature Physics, Published online 17 October 2016, [DOI:10.1038/nphys3904]

Shagam Y., Klein A., Skomorowski W., Yun R., Averbukh V., Koch C. P. & Narevicius E., "Molecular hydrogen interacts more strongly when rotationally excited at low temperatures leading to faster reactions", (2015) Nature Chemistry, 7, 11, p. 921-926

#Lavert-Ofir E., Shagam Y., Henson A. B., Gersten S., Klos J., Zuchowski P. S., Narevicius J. & Narevicius E., "Observation of the isotope effect in sub-kelvin reactions", (2014) Nature Chemistry, 6, 4, p. 332-335

Henson A. B., Gersten S., Shagam Y., Narevicius J. & Narevicius E.."Observation of Resonances in Penning Ionization Reactions at Sub-Kelvin Temperatures in Merged Beams", (2012) Science, 338, 6104, p. 234-238

B. Margulis, J. Narevicius, E. Narevicius , "Direct Observation of a Feshbach-resonance by Coincidence-detection of Ions and Electrons in Penning Ionization Collisions", (2020) Nature Communications. 11, 3553

Observation of molecular dynamics with quantum state resolution is one of the major challenges in chemical physics. Complete characterization of collision dynamics leads to the microscopic understanding and unraveling of different quantum phenomena such as scattering resonances. Here we present an experimental approach for observing molecular dynamics involving neutral particles and ions that is capable of providing state-to-state mapping of the dynamics. We use Penning ionization reaction between argon and metastable helium to generate argon ion and ground state helium atom pairs at separation of several angstroms. The energy of an ejected electron carries the information about the initial electronic state of an ion. The coincidence detection of ionic products provides a state resolved description of the post-ionization ion-neutral dynamics. We demonstrate that correlation between the electron and ion energy spectra enables us to directly observe the spin-orbit excited Feshbach resonance state of HeAr+. We measure the lifetime of the quasi-bound HeAr+ A2 state and discuss possible applications of our method.

A. Luski, Y. Segev, R. David, O. Bitton, H. Nadler, A. R. Barnea, A. Gorlach, O. Cheshnovsky, I. Kaminer, E. Narevicius , "Vortex beams of atoms and molecules", Science. 373, 6559, p. 1105-1109 (2021)

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